The game of football is usually associated with attributes like power, speed and aggression. But football can be very cerebral as well, with deception and strategy playing a major part.

One of the most common deceptive techniques found on the field is the play-action pass, where the entire offense sells a run but then executes a pass.

The concept seems simple, but it takes 11 guys doing their job to execute a play-pass properly. If the offense gives the appearance of a run, the defense will be out of position, sometimes only for a split second. That can open up holes in the pass coverage. Then the quarterback can throw short to the flat, intermediate routes over drawn-in linebackers or even a try big play downfield, taking advantage of an overaggressive safety.

It can be a devastating weapon for an offense that has a respectable rushing attack.

"That is part of our blueprint of how we do things," offensive coordinator John Morton said. "We try to establish the run game and then play-action off it. It helps out where we have a chance to take some shots against eight-man boxes and see if we can get the big play."

To execute play-action properly, everything starts up front with the offensive line. The linemen have to come off the ball and sell the run to have any chance of getting the linebackers to bite on the fake.

"We want them to sell the run, but they have to maintain control," offensive line coach Pat Ruel said. "If you are out of control, you can give up a sack on a play-action pass.

"It is kind of a hard thing to teach, blocking with aggression but controlled aggression. Where they have the ability to come off [like a run], but then move their feet and stay in front of people."

Ruel likes to call it "high pressure control," where his linemen come off the ball a little higher, into the chest of the defensive linemen. After that initial surge, they need to move their feet and keep themselves between the defender and the quarterback, allowing him time to find his target and complete the pass.

Outside, the receivers and tight ends must appear to be blocking for a running play before breaking off into their routes. The quarterback should pretend to hand the ball off, hide it and then look back up field to find a receiver. And the running back must act like he has the ball before either staying in for protection or heading out into a pass pattern.

"The running backs should act exactly like they are getting the ball," running backs coach Todd McNair said. "They just need to make sure they carry out their fakes and make it as realistic as possible so the linebackers bite on it.

"You can't have a different body posture as you are starting your footwork or they won't believe it is a run."

It takes a bit of acting, and sometimes overacting, for the backs to execute a great fake.

"You try to over exaggerate it a lot, cuff it, put your head down and run hard for at least three steps to make the linebackers come in," tailback Allen Bradford said. "If you get tackled then you are doing your job."

Backs also have to be aware of what the defense is doing. If a blitz is on, adjustments need to be made.

"They only time they abort the fake aspect of it is if somebody is coming and they have to pick up a blitz," McNair said.

While there are several advantages of running play-action like getting the defense up, helping out with protection, getting the QB on the move and providing an opportunity for a big play, there can be disadvantages as well.

One issue is that the quarterback has to take his eyes off of the defense while executing the fake handoff. That means the QB must rely on his pre-snap reads of the defense, and if he sees something he doesn't like, he may have to audible out of the play.

Play-action can also create some holes in the protection with certain defensive pressure schemes.

But for the USC offense, the reward clearly outweighs the risks, especially when playing against an aggressive defense like they do in practice day in and day out.

"Play-action pass is really hard, especially for USC's defense, because everybody is so aggressive and run hungry," linebacker Jordan Campbell said. "We want to fly up and make the play. That is the first thing we think, come up and stop the run.

"We will crush the run, but sometimes we are flying up so hard that they just dump balls right over our heads."

To help combat the play-action pass, each group of defenders has to stay aware and watch for any signs of deception coming from the offense.

For the defensive line the objective is simple, a quick conversion from run mode to pass mode.

"You just have to convert," defensive line coach Jethro Franklin said. "You are all geared to playing the run and it turns out to be a pass, so the defensive linemen have to convert.

"On the back end you have to play disciplined. If you are supposed to be deep, then you stay deep and you have to key on your keys. If you do that, you shouldn't have a problem."

In the secondary, the safety has several things to be aware of when trying to spot a play pass.

"It all depends on personnel, keys, their splits and stuff," safety Will Harris said. "Who is at running back? Who is at receiver? Who is at tight end?"

For a strong safety like Harris, the tight end is where most of his attention is focused.

"Where is the tight end looking when he is down in his stance?" Harris said. "If he is looking up at the defensive linemen, then I am going [to stop the run]. If he is looking back, I stay back [to protect against the pass]."

To prevent the linebackers from getting sucked in, watching some pre-snap keys of the offensive linemen and running backs can make a major difference.

"If the back is five yards deep he is usually pass-blocking because he has to get up to the line quicker," Campbell said. "But if he is eight yards deep it is usually a run because he needs the steps to time out his cuts and stuff."

Closely watching hands on the ground is another way to tell if a lineman or back is preparing to run block or pass-protect. If you see white knuckles, it usually means that they are leaning forward.

"If he is leaning heavy, he is coming downhill to block," Campbell said. "If he is light, he is usually running a pass route [or pass-protecting]."

Of course, an offense that is better at running the ball and executing the fake will have more success at play-action passing.

"Some run it better than others," Franklin said. "Some teams you can tell; other teams you can't. Usually the more athletic you are, the harder it is to tell."

With an athletic offensive line and great stable of running backs, the Trojan offense runs a formidable play-action game.

"They are pretty darn good," Franklin said. "We get to practice against it a lot. They have their favorite runs and off those runs they have play-action off it, so it makes it tough."

That toughness will make defending against the play-pass a bit easier for the USC defense.

"We definitely get a good look at play-action from our offense (in practice) and that should help us during the season," Campbell said.

Stay tuned to USCFootball.com for the most in-depth coverage of USC Football and the 2009 fall camp action.